C. V. Krishnamohan Sharma

X-Ray crystal structure of C6H3(CO2H)3-1,3,5·1.5(4,4′-bipy): a ‘super trimesic acid’ chicken-wire grid

Trimesic acid cocrystallizes with 1.5 equivalents of 4,4′-bipyridine to generate a large distorted hexagonal network with ca. 35 × 26 A internal dimensions: three independent networks interweave to afford a novel threefold two-dimensional corrugated sheet.

‘Molecular Chinese blinds’: self-organization of tetranitrato lanthanide complexes into open, chiral hydrogen bonded networks

Lanthanide ions, with their unique electronic properties, rich stereochemistry, and consistent structural patterns offer a novel approach to the design of polar/chiral networks.

Crystal structures of two 1,2-bis-(1-aryl-3-methyltriazene-3-yl-)ethanes with aryl substituents of opposite polarity

The crystal and molecular structure of 1,2-bis-{1-(2-cyanophenyl)-3-methyltriazen-3-yl-}ethane (1) and 1,2-bis-{1-(2-methoxyphenyl)-3-methyltriazen-3-yl-}ethane (2) have been determined by single crystal X-ray diffraction analysis. Bis-triazene (1) exists as the “staggered” conformation in the solid state, with an anti-anti configuration around the N2–N3 bond of the triazene units, whereas 2 assumes a “gauche” conformation with the syn-syn configuration in the triazene units. Crystal data: 1 C18H18N8, triclinic, space group P −1, a = 6.108(2), b = 8.118(3), c = 9.600(4)Å, α = 101.37(7)°, β = 96.47(7)°, γ = 102.71(5)°, V = 449.1(3)Å3, Z = 2; 2 C18H24N6O2, monoclinic, space group P 21/n, a = 13.119(5), b = 7.745(2), c = 19.201(2)Å, β = 96.47(7)°, V = 1910.3(9)Å3, Z = 4.

A SUPRAMOLECULAR CARPET FORMED VIA SELF-ASSEMBLY OF BIS(4,4'-DIHYDROXYPHENYL) SULFONE

Bis(4,4′-dihydroxyphenyl) sulfone 1 exploits its tetrahedrally disposed complementary hydrogen bonding sites to generate a unique doubly interwoven molecular carpet architecture in the solid state.

C-H⋯X (X = N,O) hydrogen bond-mediated assembly of donors and acceptors: The crystal structures of phenazine complexes with 1,4-dinitrobenzene and TCNQ

Abstract The charge-transfer complexes of phenazine:1,4-dinitrobenzene ( 1 ) and phenazine:TCNQ ( 2 ) were crystallized from a 1:1 solution mixture of methanol:acetonitrile. The donor and acceptor molecules in 1 and 2 are stacked with centroid-centroid distances of 3.61 A and 4.24 A, respectively. The crystal packing analysis of these complexes reveal planar two-dimensional structures that are stabilized by numerous C-H⋯X (X = N, O) hydrogen bonds. Alignment of donor and acceptor molecules within the sheet structures of 1 and 2 is strikingly similar. A close analogue of complex 2 , the 1:1 charge transfer complex of anthracene:TCNQ exhibits an entirely different architecture from 2 due to differences in C-H⋯N hydrogen bonding preferences.

Simple routes to supramolecular squares with ligand corners:1:1 AgI:pyrimidine cationic tetranuclear assemblies

Simple, tetranuclear cationic supramolecular squares with ligands at the corners can be constructed using the geometry of the pyrimidine ligand and the directional tendencies of AgI coordination; the 1:1 AgI:pyrimidine squares have an open channel structure which facilitates selective ion exchange of pertechnetate over nitrate.

Self-assembly of freebase- and metallated-tetrapyridylporphyrins to modified gold surfaces

Freebase- and metallated-tetrapyridylporphyrins self-organize through multiple hydrogen bonding to carboxylic acid terminated self-assembled monolayers on gold surfaces, thereby producing surfaces with two additional functional sites, the porphyrin cavity and the terminal pyridyl groups.

Perspectives of crystal engineering

“Is Materials Science going soft?” This question is raised by George Marsh in the first issue of Materials Today and certainly deserves further consideration. Crystal Engineering, one of these ‘soft’ areas in materials science, has recently been emerging as a major cross-disciplinary field of basic and applied inquiry.

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF CYCLIC ARYL ETHERS

The facile preparation of macrocyclic ethers is achieved using S NAr reactions of (dichlorobenzene)CpFe + complexes with various dinucleophiles, followed by photolytic demetallation; X-ray crystallography gives unequivocal structural proof for one of these macrocycles.

Interdigitated supramolecular laminates

Secondary ammonium salts of trimesic acid form robust interdigitated lamellar structures which are sustained by a combination of strong hydrogen bonds in two dimensions and hydrophobic interactions in the third dimension.